Photographic material for the silver dyestuff bleaching process



United States ()1 like 3,454,401 Patented July 8, 1969 3,454,401 PHOTOGRAPHIC MATERIAL FOR THE SILVER DYESTUFF BLEACHING PROCESS Rudolf Moi-y, Dornach, Switzerland, assignor to Ciba Limited, Basel, Switzerland, a Swiss company No Drawing. Filed Feb. 2, 1965, Ser. No. 429,910 Claims priority, application Switzerland, Feb. 13, 1964, 1,701/ 64 Int. Cl. G03c 1/10, /52

US. C]. 96-99 Claims ABSTRACT OF THE DISCLOSURE Photographic materials for the silver dyestuff bleaching process that contain on a support a layer having at least one dye stuff of the formula The present invention provides photographic material for the silver dyestuff bleaching process, which material contains a cyan dyestuif in a silver halide emulsion layer. Such a dycstulf must possess a wide range of properties: it must not reduce the sensitivity of the red-sensitized emulsion; it must not ditfuse into the support layer or into the magenta layer; it must be easily and completely bleachable in the bleaching bath; it must be fast to light, and it must meet certain spectral requirements.

The present invention is based on the observation that dyestuffs of the following formula meet these requirements to a large extent. Accordingly, the present invention provides photographic materials for the silver dyestuif bleaching process that contain on a support a layer having at least one dyestufl? of the formula in which R represents the radical of a 1-acylamino-8- hydroxynaphthalene-disulfonic acid bound to the azo group in 7-position, R represents a benzene radical which is bound to the azo groups in 1:4-position and contains two alkoxy groups, one in 2-position and one in 5-position, and R represents the radical of a hydroxynaphthalene-monosulfonic acid amide or a hydroxynaphthyl-sulfone bound to the azo group in a position vicinal to the hydroxyl group. I

Dyestuifs of the kind defined can be prepared, for example, by diazotizing a l-amino-Z:5-dialkoxy-4-nitrobenzone, for example, 1-amino-2:5diethoxy 4-nitrobenzene, or a 1-amino-4-nitrobenzene that contains a methoxy group in the 2- or 5-position and an ethoxy group in the other of these two positions, but preferably 1-amino-2z5- dimethoxy-4-nitrobenzene, coupling the diazo compound with a l acylamino 8 hydroxynaphthalene disulfonic acid, reducing the nitrazo dyestuif, diazotizing the aminoazo dyestulf, and coupling the diazo-azo compound with a hydroxynaphthalene-monosul-fonic acid amide or bydroxynaphthylsulfone that couples in a position vicinal to the hydroxyl group.

Suitable 1-acylamino-8-hydroxynaphthalene-disulfonic acids are, for example, l-acylamino-8-hydroxy-naphthalene-4z6-disulfonic acids and especially l-acylarnino-8- hydroxynaphthalene-3 :6-disi1lfonic acids. The acylamino group in l-position may be derived, for example, from an aliphatic carboxylic acid, for example, propionic acid or acetic acid, but especially from an acid of the benzene series, for example, benzoic acid, benzene-sulfonic acid or para-toluene sulfonic acid. In this case, the acylamino group corresponds to the formula R Y- -NH, in which R represents a monocyclic benzene radical and Y represents an SO group or preferably a -CO- group. Accordingly, examples of l-acylamino-8-hydroxynaphthalene-disulfonic acids are l-acetylamino, l-benzoylarninoand 1para-toluenesulfonylamino-8-hydroxynaphthalene-3 :6-disulfonic acid.

The hydroxynaphthalene-monosulfonic acid amides and hydroxynaphthylsulfones to be coupled with the diazo-azo compounds must be capable of coupling in a position vicinal to the hydroxyl group and may contain the hydroxyl group in u-position or preferably in fi-position. Thus, for example, 1-hydroxynaphthalene-3-sulfonic acid amides, 2-hydroxynaphthalene-G-sulfonic acid amides and especially 2-hydroxynaphthalene-7-sulfonic acid amides and the corresponding hydroxynaphthyls lfonesare used. Substances worthy of special mention are the Z-hydroxynaphthalene-7-sulfonic acid amides of the formula in which Z represents a hydrogen atom or an alkyl group that may be further substituted, for example, a methyl, an ethyl, an n-propyl, an isopropyl, a hydroxyethyl or a methoxy propyl group, and Z represents a hydrogen atom, an alkyl group that may be further substituted, an aryl radical, for" example, a naphthyl radical or preferably a phenyl radical, or a cyeloalkyl radical, for example, a cyclohexyl radical, in which formula Z; and Z together with the nitrogen atom, may also form a heterocyclic ring, for example, a morpholine ring or a piperidine ring. The following compounds are examples:

1-hydroxynaphthalene-3-sulfonic acid-methoxypropylamide,

2-liydroxynaphthalene-6-sulfonic acid-methoxypropylamide,

Z-hydroxynaphthalene-7-sulfonic acid-methoxypropylamide,

Z-hydroxynaphthalene-7-sulfonic acid-phenylamide,

2-hydroxynaphthalene-7-sulfonic acid-cyclohexylamide,

2-hydroxyrraphthalene-7-sulfonic acid-methylamide,

2-hydroxynaphthalene-7-sulfonic acid-dimethylamide,

2-hydroxynaphthalene-7-sulfonic 'acid-isopropylamide,

2-hydroxynaphthalene-7-sulfonic acid-morpholide, 2-hydroxynaphthalene-7-sulfonic acid-ethylamide, 2-hydroxynaphthalene-7-sulfonic acid amide, 2-hydroxynaphtha1ene-7-sulfonic acid-hydroxyethylamide,

and Z-hydroxynaphthyl- (7 -benzylsulfone.

As is evident from the foregoing, the preferred dyestuffs for the photographic materials of the invention are those of the formula In these formulae, R R Z and Z have the meanings given above, X represents a sulfonic acid amide group or a benzylsulfone group, R represents an alkyl radical containing not more than 2 carbon atoms, and A reppresents an acylamino group.

A suitable method of preparing dyestuffs of the kind defined has already been indicated, and the various reactions may be carried out in the customary manner. For example, the first coupling reaction is advantageously carried out in a slightly alkaline medium, for example, in a medium containing sodium carbonate or sodium borate, reduction of the nitro compound to the amino compound is advantageously carried out with sodium sulfide in a strongly alkaline medium, and the second coupling reaction is carried out in a slightly alkaline medium in the presence of a substance that assists coupling, for example, pyridine or picoline.

The main difference between the dyestuffs of the invention and similar known dyestuffs is that the former display a very low degree of absorption in the blue range of the spectrum. They do not diffuse into the colorless support layer nor do they diffuse into the magenta layer disposed above. They bring about only a very slight decrease in the sensitivity of a red-sensitized silver bromide emulsion. They are fast to light and are not even attacked by chromium-containing oxidation baths as used in the reversal-reversal process. They can be bleached to a pure white in the usual acid dyestuff bleaching baths, and the intermediate tones of lower color density that are obtained when only a portion of the dyestuff is bleached are of the same spectral purity as the unbleached dyesuff; in particular, the color of the said intermediate tones is not shifted towards the blue-violet range. Furthermore, the color and intensity of images produced with these dyestuffs are less dependent on changes in pH than is the case with images produced with similar dyestuffs. The dyestuffs of the invention can be very easily bleached, even when in the lowest layer of multilayer material, and yield images having a flat, straight gradation. In the form of the alkali metal salts the dystuifs are readily soluble in water and produce only a slight increase in viscosity when added to a silver salt emulsion in gelatine. They are thus eminently suitable for incorporation in the red-sensitized silver bromide-gelatine emulsion layer at the bottom of multilayer material, especially for colored images to be viewed in incident light.

The following example illustrates the invention. Unless otherwise stated, the parts and percentages are by weight.

EXAMPLE A solution of 10 mg. of a dyestuff of the formula in 1.4 ml. of water is homogeneously mixed at 40 C. with 3.3 ml. of a 6% gelatine solution, 2 ml. of a 1% solution of 2-phenylamino-4 6-dichloro-1 :3 5-triazine-4'- sodium sulfonate and 3.3 ml. of a silver bromide-silver iodide emulsion containing 83 grams of gelatine and 23 grams of silver per kilogram. The mixture is cast on a glass plate measuring 13 cm. x 18 cm. The dried layer is exposed behind a stepped wedge, and the silver image is developed in a 1-methylamino-4-hydroxybenzene developer and fixed. The image dyestufi is then bleached out, depending on the amount of silver present, in a bath that contains, per 1000 parts by volume, parts of potassium bromide, 10 parts of thiourea, 70 parts by volume of hydrochloric acid of 37% strength, and 0.003 part of 2-amino-3-hydroxyphenazine. Excess silver is then removed in a bath that contains per 1000 parts by volume, 100 parts of sodium chloride, 100 parts of crystalline copper sulfate and 50 parts by volume of hydrochloric acid of 37% strength, whereupon fixation is carried out in the customary manner. A cyan wedge is obtained that constitutes the opposite image of the silver wedge orginally used and that is bleached pure white at areas Where the silver was originally most dense. A cyan image of this nature can also constitute a part of multicolor material.

The dyestuff of the Formula 6 can be prepared as follows:

39.6 parts of 1-amino-2:5-dimethoxy-4-nitrobenzene are diazotized at 0 C. in the usual manner with hydrochloric acid and sodium nitrite. The clear diazo solution is coupled with a solution of 84.6 parts of l-benzoylamino-8-hydroxynaphthalene-3:6-disulfonic acid in 1000 parts by volume of water in the presence of an excess of sodium borate. Coupling begins quickly and is completed by stirring the reaction mixture for several hours at room temperature. The nitroazo dyestutf precipitates in the form of small pale violet needles. It is isolated by suction filtration and then thoroughly pressed. The dyestutf is then stirred into 2000 parts by volume of water, rendered alkaline, and then reduced to the aminoazo dyestuff at 40 to 50 C. in the course of half an hour with 50 parts of sodium sulfide of 62% strength. The aminoazo dyestuff is precipitated with sodium bicarbonate and sodium chloride, isolated by filtration and then purified by reprecipitation from a boiling and filtered aqueous solution using sodium chloride.

6 parts of the aminomonoazo dyestuff so obtained, or an equivalent salt-containing amount thereof, are diazotized with hydrochloric acid and sodium nitrite and then coupled with 2.37 parts of 2-hydroxynaphthalene-7-sulfonic acid monomethylamide in a medium made alkaline with sodium carbonate in the presence of picoline. The dyestufi is then purified by repeated reprecipitation with sodium acetate in aqueous solution and then carefully washed with ethanol until free from salt.

The 2-hydroxynaphthalene-7-sulfonic acid-monomethylamide used in the second coupling reaction is obtained [by carbethoxylating 2 hydroxynaphthalene 7 sulfonic acid, preparing the sulfonic acid chloride with the aid of phosphorus pentachloride or with thionyl chloride in the presence of dimethylforma-mide, condensing the chloride with monomethylamine, and subsequently splitting off the carbethoxy residue with dilute sodium hydroxide solution. It melts at 130 to 132 C.

In addition to the dyestufl of Formula 6 a number of further dyestuffs and their absorption maxima are listed in the following table. Cyan layers for the silver dyestufi bleaching process and color images can be produced with these dyestuffs by the above process. The dyestuffs themselves can also be produced by the process described above. The l-acylamino-S-hydroxynaphthalene disulfonic acid listed in column I as first coupling component is coupled with the diazo compound of the amine listed in column II, the nitroazo dyestufi is reduced to the aminoazo dyestuif, and this is followed by diazotization and coupling with the hydroxynaphthalene sulfonic acid amide or sulfone listed in column III as second component. The absorption maxima listed in column IV in m are determined by measuring gelatine layers containing 3 mg./dm. of dyestulf in a Hardy spectrophotometer.

in which R represents the radical of a 1-acylamino-8- hydroxynaphthalene disulfonie acid bound 'to the azo group in 7-position, R represents a benzene radical which is bound to the azo groups in 1:4-position and contains two alkoxy groups, one in 2-position and theother in 5- position, and R represents a radical selected from the group consisting of a hydroxynaphthalene-monosulfonic acid amide and a hydroxynaphthylsulfone, R being bound to the azo group in a position vicinal to the hydroxyl group. I

2. Photographic material for the silver dyestufl? bleaching process that contains on a support a silver halide gelatine emulsion layer having at least one dyestufl? of the formula in which R represents the radical of a 1-acylamino-8- hydroxynaphthalene-disulfonic acid boundto the azogroup in 7-position, each R represents an alkyl radical con taining at most 2 carbon atoms, X represents a member I II III IV No. 1st Coupling Component Diazo Compound of 2nd Coupling Component a 1 l-benzoylamino-B-hydroxynaphtha- 1-amino-2z5-dimethoxy-4- 2-hydrOxyna-phthalenefl-sulfonic 610 lene-3z6-disu1ionic acid. nitrobenzene. acid-methy 2 do do 2-hydroxynaphthalene-7-sull'onic 608 acid-methoxypropylamide. 3-.. do 1-amin0-2:5-diethoxy-4. .....d0 594 nitrobcnzene. 4 do l-amino-zz5-dimethoxy-4- d0 608 nitrobenzene. 5 do do Z-hydroxynaphthalene-7-sulionic 605 acid amide. 6 do do 2-hydroxynaphthaleue-7-sulfonic 607 acid-ethylamide. 7 do do 2-hydroxynaphthalene-7-sulfonic 600 acid phenylamide. 8 do 1-amino-2a5-diethoxy-4- 2-hydroxynaphthalene-7-benzyl- 610 nitrobenzene. snlfone. 0 do do Z-hydroxynaphthalenc-7-sulfonic 590 acid-hydroxyethylamide. 10 do do 2-hydroxynaphthalene-7-sulionic 590 acid amide. 11 do do Z-hydroxynaphthalene-7-sulfonic 590 acid-ethylamide. 12 do do 2-hydroxynaphthalene-7-sulfonic 620 acid morpholide. 1'1 do do l-hydroxynaphthalene-il-sulfonlc 665 acid. methoxypropylamide. 14 do do. 2-hydr0xynaphthalene-esulionic 583 acid methoxypropylamide. 1 1-amino-2:5-dimethoxy-4- ..do 585 nitrobenzene. 16 1-para-to1uenesu1fony1-amino-8- do 2-hydroxynaphthalene-7-su1ionic 608 hygroxynaphthalene-L:fi-disulfonic acid dimethylamide. acl 17 do. 2-hydroxynaphthalene-7-sn1tonic 605 acid morpholide. 1R do do Z-hydroxynaphthalene-7-sullonic 660 acid phenylamide. 19 do do Z-hydroxynaphthalene-7-sulionic 625 acid cyclohexylamide. 20 do do 2-hydroxynaphthalene-7sulionic 624 acid methylamide. 21 do do 2-hydroxynaphthalene-7-sultonlc 640 acid isopropylamide. 22 o do 2hydroxynaphthalene-7-benzyl- 625 sulione. 23 1-acetylamino-S-hydroxynaphthalenedo do 603 3:6-disulfonic acid. 24 1-benzoylamlno-B-hydroxynaphthado 2-hydroxynaphthalene-7-su1ionic 615 lene4:6-disu1fonic acid. ac amide. 25.- do do 2-hydr0xynaphthalene-7-sulionic 610 acid methylamide.

What is claimed is:

1. Photographic material for the silver dyestufl? bleaching process that contains on a support a silver halide gelatine emulsion layer having at least one dyestuif of the selected from the group consisting of a sulfonic acid amide group and a benzylsulfone group, and the hydroxyl group bound to the naphthalene ring which is further substituted by X is in a position vicinal to the azo group.

3. Photographic material for the silver dyestufi bleaching process that contains on a support a silver halide gelatine emulsion layer having at least one dyestufi of the formula in which A represents an acylamino group containing a benzene ring, R represents an alkyl group containing at most 2 carbon atoms, and X reperesents a benzylsulfone group.

4. Photographic material for the silver dyestuff bleaching process that contains on a support a silver halide gelatine emulsion layer having at least one dyestuff of the formula in which A represents an acylamino group containing a atine emulsion layer having at least one dyestufi of the formula l HOaS- SOsH R-O in which R represents a monocyclic benzene radical, Y represents a member selected from the group consisting of an -SO group and a -CO group, R represents an alkyl group containing at most 2 carbon atoms, Z rep resents a member selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group and, together with N and Z a heterocyclic ring, and Z represents a member selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, a benzene radical, a cyclohexyl radical and, together with N and Z a heterocyclic ring.

6. Photographic material for the silver dyestufi bleaching process that contains on a support a silver halide gelatine emulsion layer having the dyestufr of the formula S-NH-CHa O 7. Photographic material for the silver dyestufi bleachbenzene ring, R represents an alkyl group containing at 45 ing process that contains on a support a silver halide gel- O-CO-NH 011 moOsm-Ifn on atine emulsion layer having the dyestulf of the formula I H O 8. Photographic material for the silver dyestufi bleaching process that contains on a support a silver halide gelatine emulsion layer having the dyestuff of the formula 9. Photographic material for the silver dyestutf bleaching process that contains on a support a silver halide gelatine emulsion layer having the dyestuff of the formula HOaS- -SOaH HaC-O 10. Photographic material for the silver dyestuif References Cited bleaching process that contains on a support a silver halide gelatine emulsion layer having the dyestutf of the formula UNITED STATES PATENTS 20 2,856,397 10/1958 Pfitzner et a1 -4 260151 O0 .NE on 0-911 110 3,157,508 11/1964 DIEYfllSS 9699 3,287,132 11/1966 Hunt 9699 =N- -N=N I TRAVIS BROWN, Primary Examiner. so H I 25 HO S H=Co 0\;

a -NH:

CASE TEL-9/E 22x 3? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,454,401 Dated July 8, 1969 Inventor s) RUDOLF MORY It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 7, lines 20 to 25, amend the right hand side of the formula to read:

Signed and sealed this 25th day of May 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

